Solar cell module and method for manufacturing solar cell module

Abstract

To provide a solar cell module which is excellent in moisture resistance.SOLUTION: A solar cell module 1 includes a plate-like surface protective material 10, a solar cell submodule 20 and a rear face protective material 30 in this order, in which a sealing material 40 is filled between the surface protective material 10 and the rear face protective material 30. The rear face protective material 30 has a plurality of sheet-like garment parts 31 which each have resin layers 311 and 313 and a metal layer 312 and have mutually overlapping ends, and a moisture-proof adhesive 32 which is interposed in the overlapping regions of the garment parts 31 so as to bond the plurality of garment parts 31, extends to both sides from the overlapping regions, and is swollen so as to face the end faces of the garment parts 31.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a solar cell module and a method for manufacturing a solar cell module.

Background Art

[0002] Solar cell modules in which a plurality of solar cell sub-modules are sealed between a plate-shaped front surface protective material and a back surface protective material with a sealing material are widely used. Further, depending on the application, solar cell modules having a three-dimensional curved surface are also being considered. When manufacturing a solar cell module having a three-dimensional curved surface, it is not practical to form each component in a three-dimensional curved shape due to problems such as productivity. Therefore, a solar cell module having a three-dimensional curved surface is generally manufactured by preparing a front surface protective material having a desired three-dimensional shape and bending and stacking other members along the front surface protective material.

[0003] Regarding a solar cell module having a three-dimensional curved surface, in order to conform to the three-dimensional shape of the front surface protective material, it has been proposed to provide the back surface protective material in a plurality of divided parts. When dividing the back surface protective material, in order to prevent a decrease in design quality due to the gap of the back surface protective material being visually recognized when viewed from the light-receiving surface side or the solar cell sub-module being visually recognized from the gap of the back surface protective material when viewed from the back surface side, it has also been proposed to arrange a separate member so as to straddle adjacent back surface protective materials (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Among solar cell sub-modules, there are some that are relatively vulnerable to moisture, such as perovskite solar cells. When dividing the back surface protective material, there is a risk that the solar cell sub-module may be easily deteriorated due to the intrusion of moisture from the gaps in the back surface protective material. Since moisture can penetrate into the interior through the fine gaps in the back surface protective material, simply covering the gaps in the back surface protective material with a separate member cannot sufficiently suppress the intrusion of moisture.

[0006] Therefore, an object of the present invention is to provide a solar cell module having excellent moisture resistance and a method for manufacturing the same.

Means for Solving the Problems

[0007] A solar cell module according to an aspect of the present invention is a solar cell module including a plate-shaped front surface protective material, a solar cell sub-module, and a back surface protective material in this order, and a sealing material is filled between the front surface protective material and the back surface protective material. The back surface protective material has a resin layer and a metal layer, respectively, and a plurality of covering portions in a sheet shape whose ends overlap each other, and a moisture-proof adhesive that is interposed in the overlapping region of the covering portions so as to bond the plurality of covering portions, extends from the overlapping region to both sides, and bulges so as to face the end surfaces of the covering portions.

[0008] In the above-described solar cell module, the moisture-proof adhesive may also be disposed on the outer peripheral portion of the back surface protective material, and the front surface protective material and the covering portion may be adhered.

[0009] In the above-described solar cell module, the metal layer may be in contact with the moisture-proof adhesive.

[0010] In the above-described solar cell module, the end portion of the resin layer may recede so as to bring the metal layer into contact with the moisture-proof adhesive inside the overlapping region.

[0011] In the above-described solar cell module, the metal layer may be formed of aluminum.

[0012] In the above solar cell module, the moisture-proof adhesive may be a butyl rubber-based thermoplastic adhesive.

[0013] The above solar cell module may further include a lead wire that crosses the overlapping region through the moisture-proof adhesive and outputs electric power from the solar cell sub-module to the outside.

[0014] In the above solar cell module, the surface protective material may have a three-dimensional curved surface.

[0015] A method for manufacturing a solar cell module according to an aspect of the present invention is a method for manufacturing a solar cell module in which a first sealing material sheet, a solar cell sub-module, a second sealing material sheet, and a plurality of sheet-like covering portions whose ends overlap each other are laminated in this order on a plate-like surface protective material and then thermally pressed. Each of the plurality of covering portions has a resin layer and a metal layer, and during the thermal pressing, a strip-shaped moisture-proof adhesive having a width larger than the width of the overlapping region of the covering portions is arranged so as to extend from both sides of the overlapping region.

Advantages of the Invention

[0016] According to the present invention, a solar cell module excellent in moisture resistance can be provided.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. For the sake of convenience, hatching, reference numerals of members, etc. may be omitted, but in such a case, other drawings shall be referred to. Also, the dimensions of various members in the drawings are adjusted for easy viewing for the sake of convenience.

[0019] FIG. 1 is a schematic back view showing the configuration of a solar cell module 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line X-X of the solar cell module 1 in FIG. 1. The solar cell module 1 includes a plate-shaped front protective material 10, a solar cell sub-module 20 disposed on the back side of the front protective material 10, and a back protective material 30 covering the back side of the solar cell sub-module 20 in this order, and further includes a sealing material 40 filled between the front protective material 10 and the back protective material 30, and a lead wire 50 for outputting electric power from the solar cell sub-module 20 to the outside.

[0020] The front protective material 10 covers a plurality of solar cell sub-modules 20 via the sealing material 40. The front protective material 10 is a structural material that protects the plurality of solar cell sub-modules 20 and determines the overall shape of the solar cell module 1. Therefore, the front protective material 10 is made of a material having sufficient mechanical strength and excellent in light transmittance and weather resistance. Further, the front protective material 10 can have a three-dimensional curved surface shape and preferably has a substantially constant thickness.

[0021] Specific materials for forming the front protective material 10 include, for example, transparent resins such as acrylic resin or polycarbonate resin, glass, and laminates thereof. Also, the surface of the front protective material 10 may be processed into an uneven shape or coated with an antireflection coating layer in order to suppress reflection of light. Further, the front protective material 10 may have a light-shielding region colored black at an outer edge portion or the like where the solar cell sub-module 20 is not disposed on the back side.

[0022] The solar cell sub-module 20 is disposed along the surface protection material 10 via the layer of the encapsulant 40. The solar cell module 1 preferably includes a plurality of solar cell sub-modules 20 so as to be disposed along the surface protection material 10 having a three-dimensional curved surface shape. As the solar cell sub-module 20, for example, a string connecting crystalline silicon solar cells may be used, but typically, a perovskite solar cell sub-module in which a plurality of sub-cells having a photoelectric conversion layer containing a perovskite compound are formed on a substrate is used. When the solar cell sub-module 20 is a perovskite solar cell sub-module that is relatively easily deteriorated by moisture, the effect of preventing deterioration of the solar cell sub-module 20 by adopting the configuration of the back surface protection material 30 according to the present invention described later becomes remarkable. The solar cell sub-module 20 having a perovskite photoelectric conversion layer may be formed by laminating on the surface protection material 10, that is, using the surface protection material 10 as a substrate, but when the surface protection material 10 has a three-dimensional curved surface shape, it is assumed to be formed on a substrate independent of the surface protection material 10 from the viewpoint of productivity.

[0023] The back surface protection material 30 protects the solar cell sub-module 20 by covering the solar cell sub-module 20 via the encapsulant 40. The back surface protection material 30 has flexibility in order to follow the three-dimensional shape of the surface protection material 10. The back surface protection material 30 has a plurality of covering portions 31 in the form of sheets whose ends overlap each other, and a moisture-proof adhesive 32 interposed in the overlapping region of the covering portions 31 and extending from the overlapping region to both sides. In FIG. 1, for clarity, the moisture-proof adhesive 32 exposed on the back surface is hatched. Note that the plurality of covering portions 31 may be partially connected to each other. As a specific example, as shown in FIG. 3, the plurality of covering portions 31 may be formed by forming cuts 314 in a single substrate, and the ends defined by the cuts 314 may be formed so as to overlap each other.

[0024] The covering part 31 has at least one resin layer and at least one metal layer, and preferably, the surface facing the solar cell sub-module 20 is the resin layer. In the present embodiment, each covering part 31 has a first resin layer 311, a metal layer 312, and a second resin layer 313 in this order from the side of the solar cell sub-module 20. The first resin layer 311 and the second resin layer 313 have insulating properties. In particular, the first resin layer 311 covers the metal layer 312 to prevent a short circuit caused by the solar cell sub-module 20 or a wiring material (not shown) connected to the solar cell sub-module 20 coming into contact with the metal layer 312. Examples of the resin forming the resin layers 311 and 313 include polyethylene terephthalate (PET), polyethylene (PE), fluorine-containing resin, silicone resin, etc., and may contain a colorant such as a black pigment to improve the designability of the solar cell module 1. The metal layer 312 prevents the permeation of moisture and ensures moisture-proof properties. The metal layer 312 is preferably formed of aluminum, which is relatively inexpensive and has excellent moisture-proof (rust-proof) properties. In the solar cell module 1, it is preferable that the metal layer 312, which has a higher adhesive strength than the resin layers 311 and 313 with respect to the moisture-proof adhesive 32, is in contact with the moisture-proof adhesive 32. For this reason, the resin layers 311 and 313 may be recessed so as to bring the metal layer 312 into contact with the moisture-proof adhesive 32 inside the overlapping region.

[0025] The moisture-proof adhesive 32 adheres the covering parts 31 to each other. Further, the moisture-proof adhesive 32 is provided so as to extend from both sides of the overlapping region of the covering part 31 at least in the region facing the solar cell sub-module 20, thereby preventing the formation of a bonding defect that can be the starting point of peeling of the moisture-proof adhesive 32 at the end of the covering part 31. Further, the moisture-proof adhesive 32 bulges along the end face of the covering part 31 and has a bulging part 321 facing the end face of the covering part 31. The bulging part 321 prevents a short circuit caused by the solar cell sub-module 20 or a wiring material connected to the solar cell sub-module 20 coming into contact with the metal layer 312.

[0026] The moisture-proof adhesive 32 is preferably disposed between the clothing part 31 and the front surface protective material 10 at the outer peripheral portion of the back surface protective material 30 to bond the clothing part 31 and the front surface protective material 10. In this case, the back surface protective material 30 has a smaller planar dimension than the front surface protective material 10, and it is more preferable that the moisture-proof adhesive 32 at the outer peripheral portion of the back surface protective material 30 extends outward from the clothing part 31 and also has a bulging portion 321 at a position facing the end surface of the outer periphery of the clothing part 31. Thereby, the gap between the front surface protective material 10 and the back surface protective material 30 at the outer peripheral portion of the sealing material 40 is sealed, and the intrusion of moisture from the outer peripheral portion into the sealing material 40 can also be suppressed.

[0027] The moisture-proof adhesive 32 preferably has a melt flow rate (JIS-K7210-1) sufficiently smaller than that of the sealing material 40 so as not to be washed away by the sealing material 40 during the sealing (assembly) of the solar cell sub-module 20. As the specific melt flow rate MFR (190 ° C, 21.2 N) of the moisture-proof adhesive 32, 10 g / 10 min or more and 1000 g / 10 min are preferable.

[0028] As the moisture-proof adhesive 32, a thermoplastic adhesive is preferably used so as to be able to bond the clothing part 31 during the sealing of the solar cell module 1. Among them, a butyl rubber-based thermoplastic adhesive which is excellent in moisture-proof property and can have a relatively high melt flow rate is particularly preferably used. Further, the moisture-proof adhesive 32 may contain moisture-absorbing particles. As the moisture-absorbing particles contained in the moisture-proof adhesive 32, for example, silica gel, alumina, zeolite, and talc are preferably used. Thereby, it is possible to more reliably prevent moisture from reaching the photoelectric conversion layer 13.

[0029] As the lower limit of the average thickness of the moisture-proof adhesive 32 in the overlapping region of the covering part 31, 10 μm is preferable, and 100 μm is more preferable. On the other hand, as the upper limit of the average thickness of the moisture-proof adhesive 32 in the overlapping region of the covering part 31, 1.0 mm is preferable, and 0.5 mm is more preferable. By setting the average thickness of the moisture-proof adhesive 32 in the overlapping region of the covering part 31 to be equal to or greater than the lower limit, the covering part 31 can be reliably adhered. Further, by setting the average thickness of the moisture-proof adhesive 32 in the overlapping region of the covering part 31 to be equal to or less than the upper limit, the intrusion of moisture through the moisture-proof adhesive 32 can be suppressed.

[0030] As the lower limit of the average protruding height from the adjacent covering parts 31 so that the end faces of the moisture-proof adhesive 32 face each other, 100 μm is preferable, and 300 μm is more preferable. On the other hand, as the upper limit of the average protruding height of the moisture-proof adhesive 32 from the covering part 31, 2.0 mm is preferable, and 1.0 mm is more preferable. By setting the average protruding height of the moisture-proof adhesive 32 from the covering part 31 to be equal to or greater than the lower limit, in addition to being able to reliably cover the end face of the back surface protective material 30 with the moisture-proof adhesive and suppress the intrusion of moisture, it is possible to reliably prevent contact between the wiring material connected to the solar cell sub-module 20 or the solar cell sub-module 20 and the metal layer 312. Further, by setting the average protruding height of the moisture-proof adhesive 32 from the covering part 31 to be equal to or less than the upper limit, it is possible to reduce the thickness of the solar cell module 1 while preventing the moisture-proof adhesive 32 from interfering with the solar cell sub-module 20.

[0031] As the lower limit of the average extension width (average extension length from the end face of the covering part 31) of the covering part 31 from the overlapping region at the end of the moisture-proof adhesive 32, 1 mm is preferable, and 3 mm is more preferable. On the other hand, as the upper limit of the average extension width of the moisture-proof adhesive 32, 30 mm is preferable, and 20 mm is more preferable. By setting the average extension width of the moisture-proof adhesive 32 to be equal to or greater than the lower limit, the intrusion of moisture and short circuit can be reliably prevented. Further, by setting the average extension width of the moisture-proof adhesive 32 to be equal to or less than the upper limit, degrees of freedom in the design of the covering part 31 can be obtained.

[0032] The encapsulant 40 is filled in the space between the front surface protective material 10 and the back surface protective material 30, integrally holds each component, and prevents oxygen, moisture, etc. from contacting the solar cell sub-module 20. As the encapsulant 40, for example, a resin having translucency such as ethylene / vinyl acetate copolymer (EVA), ethylene / α-olefin copolymer, ethylene / vinyl acetate / triallyl isocyanurate (EVAT), polyvinyl butyrate (PVB), acrylic resin, urethane resin, or silicone resin is preferably used. The encapsulant 40 preferably has thermoplasticity that penetrates into the gaps of the solar cell sub-module 20 during the manufacturing stage and is formed from a material that can maintain its shape even when the temperature of the solar cell module 1 rises due to the loss of thermoplasticity in the final product. That is, the encapsulant 40 is preferably formed of a resin composition mainly composed of a thermoplastic resin and containing a crosslinking agent that activates at a temperature higher than the softening point of the thermoplastic resin and crosslinks and cures the thermoplastic resin.

[0033] The lead wire 50 passes through the moisture-proof adhesive 32 and crosses the overlapping region, thereby exposing one end to the outside. By covering the front and back of the lead wire 50 with the moisture-proof adhesive 32, it is possible to prevent the formation of a gap along the lead wire 50 in the back surface protective material 30.

[0034] The above solar cell module 1 can be manufactured by an embodiment of a method for manufacturing a solar cell module according to the present invention. One embodiment of the method for manufacturing a solar cell module capable of manufacturing the solar cell module 1 is that, on a plate-shaped surface protection material 10, a first encapsulant sheet forming the surface side portion of the encapsulant 40, a solar cell sub-module 20, a second encapsulant sheet forming the back side portion of the encapsulant 40, and a plurality of sheet-like covering portions 31 whose ends overlap each other are thermally pressed in this order. The plurality of covering portions 31 each have resin layers 311 and 313 and a metal layer 312. During the thermal pressing, a strip-shaped moisture-proof adhesive 32 having a width larger than the width of the overlapping region of the covering portions 31 is arranged so as to extend from the overlapping region to both sides between the overlapping covering portions 31. Note that the moisture-proof adhesive 32 may be partially laminated multiple times, for example, at the corners of the covering portions 31. Also, in a region where three or more covering portions 31 are laminated, the moisture-proof adhesive 32 is arranged on both the front and back sides of one covering portion 31. By thermal pressing such a laminate, the moisture-proof adhesive 32 in the overlapping region of the covering portions 31 is compressed in the thickness direction and pushed out to the outside of the overlapping region. Therefore, as described above, the portions on both sides of the overlapping region of the moisture-proof adhesive 32 bulge so as to face the end surfaces of the covering portions 31.

[0035] The solar cell module 1 that can be manufactured in this way and has the above-described configuration overlaps the ends of the plurality of covering portions 31 having the metal layer 312 and adheres them with the moisture-proof adhesive 32, causing the moisture-proof adhesive 32 to protrude outside the overlapping region of the covering portions 31 and forming a bulging portion 321 facing the end surfaces of the covering portions 31. This can more reliably suppress the intrusion of moisture into the interior and prevent a short circuit due to contact with the metal layer 312.

[0036] As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various changes and modifications are possible.

Explanation of Reference Numerals

[0037] 1 Solar cell module 10 Surface protection material 20 solar cell sub-modules 30 backside protective material 31 covering part 311 first resin layer 312 metal layer 313 second resin layer 32 moisture-proof adhesive 321 bulging part 40 encapsulant 50 lead wire

Claims

1. A solar cell module comprising a plate-shaped front surface protective material, a solar cell sub-module, and a back surface protective material in this order, with a sealing material filled between the front surface protective material and the back surface protective material, wherein the back surface protective material, has a resin layer and a metal layer respectively, a plurality of sheet-like covering portions whose ends overlap each other, a moisture-proof adhesive interposed in the overlapping region of the covering portions so as to bond the plurality of covering portions, extending from both sides of the overlapping region, and bulging to face the end faces of the covering portions, and a solar cell module having the same.

2. The solar cell module according to claim 1, wherein the moisture-proof adhesive is also disposed on the outer peripheral portion of the back surface protective material and bonds the front surface protective material and the covering portion.

3. The solar cell module according to claim 1 or 2, wherein the moisture-proof adhesive is in contact with the metal layer.

4. The solar cell module according to claim 3, wherein the end of the resin layer recedes so as to bring the metal layer into contact with the moisture-proof adhesive inside the overlapping region.

5. The solar cell module according to claim 1 or 2, wherein the metal layer is made of aluminum.

6. The solar cell module according to claim 1 or 2, wherein the moisture-proof adhesive is a butyl rubber-based thermoplastic adhesive.

7. The solar cell module according to claim 1 or 2, further comprising a lead wire that crosses the overlapping region through the moisture-proof adhesive and outputs electric power from the solar cell sub-module to the outside.

8. The solar cell module according to claim 1 or 2, wherein the front surface protective material has a three-dimensional curved surface.

9. A method for manufacturing a solar cell module, in which a first sealing material sheet, a solar cell sub-module, a second sealing material sheet, and a plurality of sheet-like covering portions whose ends overlap each other are laminated in this order on a plate-shaped front surface protective material and then hot-pressed, wherein the plurality of covering portions each have a resin layer and a metal layer, and in the hot pressing, a strip-shaped moisture-proof adhesive having a width larger than the width of the overlapping region of the covering portions is disposed so as to extend from both sides of the overlapping region between the overlapping covering portions.

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